The present invention relates to a nozzle for an air supply device for capturing and deflecting an air flow passing through the device, and more particularly to a nozzle of the kind defined in the preamble of Claim 1. The invention also relates to an air supply device provided with one or more such nozzles.
Nozzle-equipped air supply terminal devices of the kind concerned in this document, e.g. devices marketed under the trade name REPUS(copyright), find versatile use for the draught-free supply of attemperated air to different types of locales, including offices and living accommodations. The air blown into the locale from device has a low impulse and the device can therefore often be placed in the immediate vicinity of a working place and therewith ensure that the air present therein will be of a much better quality than would otherwise have been the case.
When cooled air is delivered to an air supply terminal device of the aforesaid kind, it is preferred to mix air from the occupied zone of the room in question with the cooled air in suitable proportions, which is expedient in avoiding cold draughts in the proximity of the floor of the room.
The air jets or nozzles used in such air supply devices for capturing and deflecting air flowing through the device in a main stream direction are either fixed or moveable, e.g. rotatably mounted in a wall of the device and normally including one or more tongues which form guide vanes or baffles and which project into the air flow and therewith deflect the same.
The wall that is equipped with one or more nozzles may be mounted within the device, although the nozzle or nozzles may, alternatively, be disposed in the outer wall of said device. In this latter case, device may have the form of an air supply duct, e.g. in classrooms, for equalizing the temperature gradient in storage locales or for defrosting windows.
The nozzles may be round and divided into chambers by partition walls which, for instance, define angles of 120xc2x0 therebetween. The tongue or tongues projecting into the air flow may have mutually different lengths.
Alternatively, the nozzles may have a generally rectangular shape with one or more curved tongues or baffles, in which case the nozzles are normally fixedly mounted.
SE-C-9600939-4 (Publication No. 508 846) (Lind) describes an air supply device in the shape of a box or a screen that includes a front wall which has disposed therein groups of slots where the groups of slots and the slots in each group are mutually equidistant. Each group of slots is provided on the inside of the wall with a nozzle module in which the number of nozzles equals the number of slots and where said nozzles are intended to deflect sub-flows repeatedly from a supplied main flow through an angle of 90xc2x0. Each nozzle is provided to this end with curved deflecting parts which project progressively further out in the direction of the main flow. The deflected sub-flows collide and exit outwardly through the slots associated with respective nozzles with a low impulse.
EP-B1-0 507 756 (Stifab) describes an air supply terminal device which comprises a distribution plate that includes a plurality of circular openings that accommodate nozzles provided with deflecting elements in the form of guide vanes or baffles that project out beyond the plane of the plate. The nozzles are mounted in the hole for both rotatable and pivotal movement, so that in one nozzle position the exiting air flow will be directed upwards and in another position will be directed horizontally.
SE-C-9600635-1 (Publication No. 511 340) (Stifab Farex) describes a further development thereof, in which the rotatable nozzles are set in different positions such that the exiting air will be caused to rotate resulting in high entrained ejection of room air.
Although these known nozzle designsxe2x80x94which have the characteristic features set forth in the preamble of Claim 1xe2x80x94enable an adjustable near zone to be achieved for directing the flow of exiting air in a desired direction, they are unable to produce uniform flow distribution. This is due, among other things, to the fact that all the tongues or baffles of the nozzle have the same shape, meaning that at least a part of the tongues will not follow the flow lines of the air.
This also applies to the nozzle described in DE 888 308 (Fourtier), which lacks outwardly projecting, curved deflecting parts on the guide vanes.
Other drawbacks with known nozzles are that such nozzles have a limited directional effect, that they can only be accommodated in a flat plate provided with holes for accommodating respective nozzles, and are expensive to produce as a result of being comparatively material consuming.
With a starting point from the aforesaid, an object of the present invention is to provide a nozzle of the aforedescribed kind that has uniform flow distribution and which allow the exiting air flow to be directed in several different planes.
Another object is to provide a nozzle which, as a result of said uniform flow distribution, enables low sound generation to be achieved and which is also inexpensive to produce. owing to the material-saving design of the nozzle.
A further object of the invention is to provide a nozzle that can be accommodated in a perforated wall of an air supply terminal device, wherein the wall may be either planar or curved to some degree without influencing the intended function of the nozzle.
Yet another object of the invention is to provide a nozzle that can be readily mounted and that can be releasably fixated in desired positions, i.e. so as to enable adjustments to be easily made when necessary.
These and other objects are fulfilled by an inventive nozzle of the kind earlier described and having the characteristic features set forth in the characterizing clause of claim 1.
Because the nozzle can be swung about a pivot axis that is perpendicular to the rotational or turning axis of the nozzle, regardless of the position to which the nozzle has been turned, the nozzle will enable the exiting flow to be directed in several different planes, therewith providing considerable improvement with respect to nozzle properties. Consequently, the nozzle can be used in several different types of air supply terminal devices with improved control possibilities.
In practice, the nozzle is suitably provided with a central tongue-holding part which extends perpendicularly to the plane of the outflow parts, and two opposing attachment elements for engagement with opposing parts of the edge surrounding the hole.
In other words, the nozzle is pivotal about said second axis, which may fall in the plane of the hole or in a plane parallel with the hole-plane.
A simple and reliable construction is obtained therewith, provided that the attachment elements are so constructed as to allow pivoting of the nozzle from a starting position through an angle of at least 30xc2x0, suitably at least 45xc2x0 and preferably at least 60xc2x0, in both directions, regardless of the position of rotation of the nozzles. A Coanda effect will occur at larger pivot angles and therewith cause will cause the air flow to adhere to the wall of the device in which the nozzle is mounted.
In one preferred embodiment, the attachment elements include hook elements that springingly engage the circumferential edge of the hole.
Such attachment elements enhances the use possibilities and flexibility of the nozzle. For example, the same nozzle can be used in holes that are not fully round and, for instance, have an oval shape and also in air supply terminal devices that have curved walls such that the hole provided in said wall will not lie in a unitary plane. The statement to the effect that the nozzle can be rotated or turned about xe2x80x9can axis passing through the center of the hole generally at right angles to the plane of said holexe2x80x9d is intended to cover the case when the wall surrounding said hole is curved.
The nozzle construction becomes particularly simple and expedient when the opposing hook elements are joined to the central holder part of the tongues and are located in the same plane as said part. The hook elements may therewith be integral with said holder part and project resiliently therefrom.
In a further embodiment, the nozzle includes two circular or approximately circular side walls parallel with the central holder part and at mutually the same distance therefrom, each of said side walls being joined to the tongues in the region of their outer ends.
These sides contribute towards stiffening the nozzle construction, so as to obviate the need of a surrounding casingxe2x80x94which represents a significant saving in material. At the same time, the nozzle will lack pockets and similar areas in which dirt, dust, etc., can collect. Instead, all parts of the nozzle are easily reached, e g. for cleaning purposes, therewith improving the hygienic properties of the nozzle.
The outside of the side walls may include centrally positioned arcuate and possibly saw tooth-configured hole-engaging parts that extend out perpendicularly to the side walls and that function to releasably fixate the nozzle in its rotational and pivotal positions. These structural features of the inventive nozzle also contribute towards its simplicity and reliability. Each side wall may include one, two or more such engagement parts.
If, as in accordance with one preferred embodiment, the curved parts of the tongues have mutually different radii, there is obtained an embodiment in which the shape of the tongues or guide vanes follows the lines of the air flow, therewith contributing towards the desired uniform flow distribution and reducing the nozzle noise.
In the case of an embodiment preferred in practice, the nozzle has three tongues, of which the third tongue or the last tongue in the direction of the main air flow lacks a curved deflecting part. Practical trials have shown that a nozzle of this design obtains optimal properties adapted to air deflection in different planes afforded by the nozzle.
It is preferred that the distances between the engagement points of the diametrically opposed hook elements and the outer points of the arcuate hole-engaging parts in their respective positions of engagement essentially correspond to one another and to the diameter of the hole. However, said distances may conveniently slightly exceed the diameter of the hole. The aforementioned outer points can therewith be said to be located on the cylindrical surface of an imaginary sphere surrounding the nozzle, the diameter of said sphere corresponding to the diameter of said hole.
It will be evident from the aforegoing that the nozzle can be fitted into the hole and removed therefrom quite easily, and that the position of the nozzle can be readily adjusted to obtain a desired flow pattern. The resilient attachment of the nozzle contributes towards the simplicity of these latter operations.
The invention also relates to an air supply terminal device of box-like, screen-like or tubular configuration, comprising a body that includes a top and a bottom wall and one or more outer and/or inner walls extending between said top and bottom walls, and means for supplying an air flow in a main flow direction parallel with one of said walls, wherein said device is characterised in that said wall includes one or more holes in which a nozzle of the aforesaid kind is accommodated.